It is known by persons skilled in the art that the display of an animation sequence may be produced in motion pictures and the like by projecting and illuminating in an intermittent, sequential manner a plurality of discrete images. Conversely, a stationary image sequence may be provided wherein the observer is in relative motion. In both instances, the principles of the phenomenon of “persistence of vision” create an effect of animation.
The general concept of having the observer move, while the images remain static has been applied in several prior instances, with varying degrees of success. In order to create a condition where the principles of persistence of vision can be applied, all prior art forms have applied some form of intermittent lighting. Most of the prior efforts to improve image quality have focussed primarily on attempts to refine complex and expensive systems of stroboscopic light sources in order to apply these principles.
Mechanical illumination triggering devices have inherent mechanical wear problems because of the high triggering rates and thus do not provide a practical solution to the problem. In addition to issues associated with maintenance and trouble free operation of mechanical parts there is a secondary and more pronounced issue, the requirement of reliable and timely triggering of image illumination. In order that the observer clearly see the image, each successive image must be illuminated at exactly the same position relative to the observer. If this process is not precise, the integration of the images will seem blurred.
In most recent inventions, the use of a stroboscopic light sources appear to have been the predominant approach to satisfying the requirement for an intermittent light source. Earlier inventions however, did provide a simpler solution to the problem.
Joseph Antoine Ferdinand Plateau invented the Phenakistiscope (a.k.a. Fantoscope) in 1932. It is basically a disc fixed at its center so that it can spin freely. Around the edges are regularly spaced slits, and in conjunction with each slit is an image drawn in a sequential stage of movement.
The German inventor Stampfer developed the Phenakistiscope separately, but at the same time; he dubbed it the Stroboscope. Many other versions and refinements followed, including a model designed by Stampfer with two fixed discs, one with a series of images, and the other with an equal number of slits or apertures centered in front of each image. Both disks rotated about a horizontal axis and a random distance between the two discs separated the image in the aperture.
In 1834, William George Homer invented the Zoetrope, an adaptation of the Stroboscope, where the axis of image rotation was transferred from a horizontal to vertical, thereby providing a substantially horizontal direction of relative image movement, while still viewed in a substantially vertical plane. A distance equal to the random diameter of the cylinder separated the image and apertures.
Unlike stroboscopic systems, both the Stroboscope and the Zoetrope employed a consistent and constant light source. In order to provide an intermittent view, an opaque plane with a series of equally spaced vertical slits or apertures were placed between the viewer and the constantly illuminated image.
To perceive an entire image through the narrow width of the aperture, both devices rely on the principles of parallax, which in turn applies the geometry and properties of the isosceles triangles. In essence, as an image proceeds into view, a longitudinal scan of the image is provided to the viewer which progress across the width of the image. The same properties apply when the device is constructed in a linear context where, the images and apertures are arranged in a vertical plane similar to the Stroboscope, while advancing the images and apertures along a horizontal plane similarly to a circular Zoetrope. This, in itself, is not a novel thought but offers a more practical arrangement where the viewer is considered to be the object in a state of relative motion.
Use of a linear arrangement of a Stroboscope, to effect persistence of vision, avoids the mechanical triggering issues and is therefore preferable to the use of a stroboscopic light source.
The widespread commercial application of a practical animation display system, based on the concepts of linear Stroboscope or Zoetrope, suitable for most environments where the viewer is in motion, would desirably first address the number of issues of commercial importance: the elimination of multiple image frames being revealed simultaneously, the ability to affect the range of possible viewing angles, the ability to adjust inappropriate frame rates particularly under conditions of relatively slow movement and the ability to adjust inappropriate image aspect ratios.
It is therefore an object of the present invention to address at least some of these drawbacks.